643543012 has 24 divisors (see below), whose sum is σ = 1328606720. Its totient is φ = 266906880.

The previous prime is 643543003. The next prime is 643543039. The reversal of 643543012 is 210345346.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369837 + ... + 371572.

Almost surely, 2^643543012 is an apocalyptic number.

643543012 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

643543012 is an abundant number, since it is smaller than the sum of its proper divisors (685063708).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643543012 is a wasteful number, since it uses less digits than its factorization.

643543012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741451 (or 741449 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 643543012 is about 25368.1495580580. The cubic root of 643543012 is about 863.3611979829.

Adding to 643543012 its reverse (210345346), we get a palindrome (853888358).

The spelling of 643543012 in words is "six hundred forty-three million, five hundred forty-three thousand, twelve".